Partial revision of IngestScheduler
Merge latest public develop branch
Tidy up DataSourceIngestPipeline and FileIngestPipeline
Fix IngestScheduler race condition and run of empty ingest pipeline
Shut down file ingest pipeline ASAP
Fix bug injected into FileIngestTaskScheduler.getNextTask()
Fix implementation of not running empty ingest pipelines
Make sure ingest job completion is always detected
Merge pull request #732 from rcordovano/ingest_scheduler_improvements

Ingest scheduler improvements